The present invention relates to conveyor systems and conveying methods and, in particular, to such systems and methods having a multi-fire mode of operation involving multiple diversion points on a single diverter, and a variable fire mode of operation involving a variable diversion point on a single diverter.
Conveyor sorting systems and methods for sorting items (e.g., packages) are common in the prior art. Conventional sorting is accomplished by providing a reader to read a preprinted code on an item to be sorted that has been placed onto the conveyor system, and thereafter activating an appropriate diverter in the proximity of the reader to cause the item to be diverted film the conveyor to an adjacent station. An exemplary prior art sorting system is described in U.S. Pat. No. 4,249,661 (the ""661 patent). Other examples of high-speed sorting apparatus are disclosed in U.S. Pat. No. 6,085,892 (the ""892 patent) and U.S. Pat. No. 5,984,498 (the ""498 patent), which patents are hereby incorporated by reference.
It is often desirable to sort items traveling on a conveyor into different bins, stackers, conveyors or other devices, referred to generically herein as xe2x80x9cstations,xe2x80x9d off to the side of the conveyer, depending on the nature of the item. Presently, this type of sorting is accomplished using a separate diverter for each station, such as illustrated in FIG. 3 of the ""661 patent. However, the need for multiple diverters for such sorting increases the complexity and expense of the conveyer system.
It is also often desirable to sort items of various size based on their position relative to the diverter. For example, for relatively long items it is often desirable to divert the item from the conveyor when its center in the long dimension reaches a mid-point of the diverter. Similarly, for relatively short items it is often preferable to activate (xe2x80x9cfirexe2x80x9d) the diverter when a different portion of the package (e.g., its leading edge) reaches the beginning of the diverter.
As described in U.S. Pat. Nos. 3,242,342, 3,515,254 and 3,512,624, it is known to divert packages from a conveyor when the center of the package reaches the mid-point of the diverter. It is also known to take various actions in a conveyor system as a function of the length of a package being conveyed. See U.S. Pat. No. 3,680,692. Unfortunately, it is believed no conveyor systems exist that determine the length of a package and then fire a diverter when a selected position on the package reaches a selected position on the diverter as a function of the length of the package. As such, known conveyor systems are not particularly well adapted to conveying packages of widely varying lengths, with the result that packages are often mis-diverted, turned in an undesirable orientation or not diverted at all.
The present invention relates to conveyor systems and methods, and in particular such systems and methods having a multi-fire operation involving multiple diversion points on a single diverter, and a combined multi-fire and variable fire operation involving a variable diversion point on one of multiple diversion points of a diverter. The invention also relates to a modular conveyor system.
A first aspect of the invention is a diverter system for diverting items to one of a plurality of stations on either side of a conveyor. The diverter system is designed for use with a conveyor for transporting items in a first direction. The conveyor includes at least one diverter region in which the diverter system is positionable. The diverter system comprises a diverter for diverting items transported by the conveyor in the first direction to one of a plurality of stations adjacent the diverter that are spaced from one another in the first direction, when positioned in a diverter region of the conveyor, in response to a fire signal. The diverter system also includes a source of destination information identifying one of the plurality of stations to which items transported by the conveyor are to be diverted, and a controller system connected to the diverter and the source for generating, and providing to the diverter, a fire signal for each item transported by the conveyor based on destination information from the source regarding the one of the plurality of stations to which the item is to be diverted.
A second aspect of the invention is a conveyor system including a conveyor having at least one diverter region. In addition, the conveyor system includes the diverter system described above, with a diverter being arranged in the diverter region of the conveyor.
A third aspect of the invention is a diverter system for diverting items having first and second item tracking points to one of a plurality of stations, each station having a central axis and a divert axis. The diverter system is designed for use with a conveyor for transporting items in a first direction, the conveyor having at least one diverter region in which the diverter system is positionable. The diverter system comprises a diverter for diverting items transported by the conveyor in the first direction to one of a plurality of stations adjacent the diverter that are spaced from one another in the first direction, when positioned in a diverter region of the conveyor, in response to a fire signal. The diverter system also includes a source of destination information identifying one of the plurality of stations to which items transported by the conveyor are to be diverted. It also includes an item measuring system for generating information representative of the length of items transported by the conveyor and for providing a length signal based on such information for each item indicating the length of the item. In addition, the diverter system includes a controller system connected to the diverter, the source and the item measuring system, for generating a fire signal for each item to be diverted and providing the fire signal to said diverter. The controller system contains information representing a first length, and the fire signal is generated for each item to be diverted based on destination information from the source regarding one of the plurality of stations to which the item is to be diverted and as a function of the length signal for such item so that the fire signal causes the diverter to divert items that are less than the first length substantially when the first item tracking point of the item arrives at the divert axis for the one of the plurality of stations and for diverting items that are greater than the first length substantially when the second item tracking point of the item arrives at the central axis for the one of the plurality of stations.
A fourth aspect of the invention is a conveyor system including a conveyor having at least one diverter region. In addition, the conveyor system includes the diverter system described in the immediately preceding paragraph, with a diverter being arranged in the diverter region of the conveyor.
A fifth aspect of the invention is a method of diverting items moving along a conveyor having a diverter to one of a plurality of stations adjacent the diverter. The method comprises, as a first step, providing destination information for each item transported by the conveyor identifying the one of the plurality of stations adjacent the diverter to which said each item is to be diverted. The method also includes the step of diverting said each item from the conveyor to said one of the plurality of stations based on said destination information for said each item.
A sixth aspect of the invention is a modular conveyor system comprising a plurality of modular conveyor sections. Each section includes (1) a conveyor for transporting items in a first direction, wherein the conveyor is connectable to conveyors in other ones of the modular conveyor sections so as to form a continuous conveyor assembly, (2) a diverter for diverting items transported by the conveyor in the first direction to one of a plurality of stations adjacent the diverter that are spaced from one another in the first direction in response to a fire signal, and (3) a controller system connected to the at least one diverter for providing a fire signal to the at least one diverter for each item to be diverted, wherein the controller system is connectable to the controller systems in other ones of the modular conveyor sections so as to permit fire signals to be communicated between the controller systems. The modular conveyor system also includes a source of destination information identifying a one of the plurality of stations in the modular conveyor system to which each item transported by the modular conveyor system is to be diverted. Also, the modular conveyor system has a host controller connected to the source and to the controller systems, wherein the host controller generates the fire signal for each item transported by the modular conveyor system based on the destination information from the source, and provides the fire signal to at least one of the controller systems.